# os.environ

The `os.environ` function returns a frozen dictionary containing a snapshot of the environment used by the script's child processes.

## Usage

```python
os.environ()
```

Keys and values are strings. The snapshot includes inherited configuration, declared environment overrides,
changes made with [`os.setenv`](/functions/automation/os.setenv), and tool directories added to `PATH` by
[`dependencies.tools`](/functions/automation/dependencies.tools). It preserves explicitly empty values.
If a variable appears more than once, its last value wins. On Windows, names are normalized to uppercase.

Each call creates an independent, read-only snapshot. Later environment changes do not update an earlier snapshot.
Per-call `env=` overrides apply only to that process and do not affect this snapshot.
The [`env`](/functions/automation/env) global continues to contain only explicitly declared step inputs.

## Examples

```python
before = os.environ()
os.setenv("REGION", "us-east-1")
after = os.environ()
print(after["REGION"])
```

Avoid printing the entire environment, which can contain credentials.

## Related

- [`os.getenv`](/functions/automation/os.getenv) reads a single variable with an optional fallback.
- [`os.setenv`](/functions/automation/os.setenv) changes a variable for subsequent calls.